It is difficult to clean a connector that has become covered in mud because access to certain portions of the connector is very restricted. Mud interferes with the mechanical and electrical operation of a connector.
In order to protect the engagable elements of a connector against mud, regardless of whether mud has been splashed onto the connector element or the connector element has been immersed in mud, proposals have been made to place a stopper on the connector element, or to provide a piston that is incorporated in the connector element and that is urged by a spring into a position in which the piston surrounds the connection members of the connector element so as to fill the space between the connection members and thus prevent mud from penetrating between the connection members.
Those techniques are not satisfactory. When a stopper is used to protect the connector element, it is necessary to remove the stopper when using the connector element to make a connection with another connector element. There is a risk that the user will forget or fail to put the stopper back into place, e.g. for lack of time. The stopper also runs the risk of being lost, or if it is attached to the connector element, it runs the risk of receiving mud or of dropping into the mud, so that it can no longer be used to reclose the connector element. With a piston, there is a risk of mud accumulating in the interstices between the connection members and the piston so that it rapidly becomes impossible to move the piston and thus disengage the connection members. Piston systems have the drawback of being complex and of requiring a connector to be relatively long, thereby making it more difficult to install, e.g. for mounting on the wall of a piece of equipment.